What Makes Sour Beer Sour?

Spoiler: sour beer does not get its flavor from sour candy.

Some people think sour beer is unnatural. “This doesn’t taste like Budweiser!” they’ll say, or “Beer was meant to be as chilly as the Rocky Mountains to the point that I can no longer taste it!”

It’s true; sour beer doesn’t taste like cheap lagers. But here’s a fun little fact: all beer used to be sour. In fact, sour beer is more natural than today’s wide variety of cheap lagers, IPAs, stouts and such.

Not to get too far into the history here, but people didn’t always have a firm understanding of yeasts. This was mostly due to the limits of science and thought in the 1800s. But once yeasts were discovered, oh boy did beer have a Renaissance. Oh boy.

At the time, different strains of yeast would be unwittingly clumped together, all of which are different types of yeasts that modern brewers use. Mixed together, you’re doomed to get at least a slightly sour flavor. But split apart, brewers can take the classic Saccharomyces cerevisiae and make a non-sour beer.

You’re probably saying something like, “this post is called ‘What Makes Sour Beer Sour,’ not, ‘Why All Beer Isn’t Sour In The Modern Era.’” True. But just because most brewers moved away from sour beers doesn’t mean everyone did. Sour yeasts remained and are still used today.

And these yeasts make beer sour.

It’s the sour beer yeast

Yes, it’s the yeast. The yeast is king.

Generally speaking, you’re going to have either the Brettanomyces or Lactobacillus yeast strain make your beer sour. When you go to your local taproom and order a sour, the brewer could probably tell you which of these (if not both) they used.

But what about sour beers with fruit in them? Well, those are brewed the same way…but with fruit. They still need the specific yeasts to get that sour flavor, and the fruit hopefully serves as a fitting complement.

And then, for our more cultured beer snobs, there’s also spontaneous fermentation and open air fermentation, often achieved through a coolship or something similar. Back in the day, this was how many beers were fermented. Today, some breweries still use this method.

Particularly the Belgians.

Belgian sours

Belgium is deservingly the most famous region for sour beers. They have some of the oldest sour beer breweries in the world, and many, like the famous Cantillon, still use spontaneous fermentation/open air fermentation to get the sour flavor.

Why don’t more people copy this method? Because it’s crazy risky. The fermentation is spontaneous, as in nobody knows what’s going in there or what it’s going to do. The result could be the worst sour beer ever to traipse this earth.

Or, it could be a revolution in sour beers that happens to smell oddly like band-aids.

Lambic vs Sour

Maybe you were recently hanging out at a friend’s house and they bust out their bitchin’ lambic beer. Ooohs and aaahs fill the room. Cantillon at its finest.

Then you sip it – it tastes sour. Why not just call it a sour beer?

Lambics are sort of like the champagne of beer, in that they are region-specific. To be a lambic, the beer technically needs to be brewed in Pajottenland, a region near Brussels in Belgium. Or, because Cantillon is basically the king of all lambics, at Cantillon’s brewery in Brussels.

Like some other Belgian sours, lambics are exposed to wild yeasts through the spontaneous fermentation process. The only difference here is that the region is home to the special yeasts and such, so the flavor profile is largely predictable (especially since they have over 100 years of brewing experience). So it’s hardly spontaneous since they know what will happen, but its’ still cool.

Tl;dr: Lambics are special sours, but not all sours are lambics.

How to enjoy sour beers

People will tell you to approach sour beers in 3 steps, like this:

  1. Try a Berlinerwiesse! A little sour but easy.
  2. Next try a Flanders Red or a lambic! That’ll step things up.
  3. DRINK EVERY SOUR

The scaling is horrible and makes no sense to me. It’s basically like convincing someone to get into beer by forcing them to try flavors they might not be interested in. In my experience, that’s how you learn to hate something.

Here’s my suggestion: go to a craft brewery near you that specializes in sours. Go up to the counter. Be honest. Tell them you don’t like/have never had sours but are curious. Nine out of ten taproom employees will give you tasters, tell you what you’re trying and take in feedback to find the right beer for you.

Once you’ve found one you think you might like, get the sour beer in a tulip glass. This commits you to 12 oz which is a little less than a pint and relatively easy to manage.

Lastly, have pretzels on hand. I swear, it’s tough to beat a sour beer with the saltiness of pretzels on the side.

Afterward, decide if you liked the beer. Did you? Cool. Did you not? Cool. I love sours, but you’ll rarely see me getting two in a row. It’s too much sour for me. Some people guzzle them like it’s their job (and it might be). That’s cool, too.

Just remember that sour beer is still beer. It might even be the OG beer. Many of today’s beer drinkers didn’t like beer the first time they tried it. The same could be said for sour drinkers. Plenty of people don’t like stouts, porters, bitter IPAs, juicy IPAs, pilsners, wild ales, etc. But they still like beer.

Sour beer is really just beer with different yeasts. Nothing too crazy about that.

Thomas Short

Thomas Short is a freelance writer based in Seattle, WA. His work has appeared in Entrepreneur, Huffington Post, The Mortgage Reports, and more. You can reach Thomas at tshortwriting.com.

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